Instance-scoped runtime key/value store for mutable Jido coordination state.

RuntimeStore is an internal control-plane store owned by each Jido instance. It backs ephemeral runtime data that needs a stable home outside individual agent processes, such as logical parent-child relationship bindings.

The ETS table itself is owned by the Jido instance supervisor, while the RuntimeStore process provides the logical API. That lets the table survive RuntimeStore process restarts without making it durable beyond the life of the owning Jido instance.

Values are organized into named hives so unrelated runtime concerns can share the same store without colliding:

:ok = Jido.RuntimeStore.put(MyApp.Jido, :relationships, "child-1", %{parent_id: "p-1"})
{:ok, binding} = Jido.RuntimeStore.fetch(MyApp.Jido, :relationships, "child-1")
:ok = Jido.RuntimeStore.delete(MyApp.Jido, :relationships, "child-1")

The store is intentionally ephemeral. It is reset when the owning Jido instance stops or restarts.